Evidence Check

A rapid review outlining the available evidence on a discrete topic or question relating to the current COVID-19 pandemic. Evidence includes grey and peer review literature. View all Evidence Checks by date of publication.

Current and emerging patient safety issues during COVID-19

Added: 17 Jun 2022
Updated: 14 Dec 2022

What is the evidence on the current and emerging patient safety issues arising from the COVID-19 pandemic?
  • There are wide-ranging reports on the indirect impacts of COVID-19 and associated mitigation strategies such as lockdowns and service shutdowns.
  • The literature not only discusses conventional patient safety issues, but also issues around delayed access to healthcare and equity issues.

Bivalent COVID-19 vaccines

Added: 16 Nov 2022

What is the available regulatory and research evidence for bivalent COVID-19 vaccines?
  • The bivalent COVID-19 vaccines have components that target both the original virus strain and the Omicron variant strain of the SARS-CoV-2 virus.
  • The Spikevax bivalent booster vaccine (Moderna, BA.1-adapted, data from an ongoing phase 2–3 trial) is found to induce stronger neutralising antibody activities against the Omicron variant (including BA.4/BA.5 subvariants) than the original booster version. It has a similar safety and reactogenicity profile to the original version.
  • The Comirnaty bivalent booster vaccine (Pfizer-BioNTech, BA.1-adapted, data from regulatory submission) is found to induce stronger neutralising antibody activities against the Omicron BA.1 subvariant than the original booster version.


Added: 14 Oct 2021
Updated: 9 Nov 2022

What is the evidence for and regulatory context of molnupiravir for treatment of COVID-19?
  • Molnupiravir (MK-4482/EIDD-2801) is an antiviral medication that is administered orally.
  • Molnupiravir is a potent ribonucleoside analogue that inhibits the viral replication of SARS-CoV-2 (or other viruses that employ RNA-dependant RNA polymerase) by introducing errors in the viral genome.
  • Despite some of evidence of risk reduction associated with molnupiravir treatment in non-hospitalised unvaccinated adults with mild to moderate COVID-19 symptoms pre-Omicron, a more recent clinical trial (pre-print) from the Omicron predominant period has suggested no risk reduction in all-cause hospitalisation or mortality among non-hospitalised vaccinated adults.
  • In real-world studies from the Omicron predominant period, molnupiravir reduced the risk of disease progression in hospitalised patients not requiring oxygen therapy on admission and who are older than 65 or not fully vaccinated. In community-dwelling outpatients with mild symptoms who are at a higher risk of progressing to severe disease, molnupiravir treatment was associated with reduced risk of all-cause mortality, hospitalisation and in-hospital disease progression in patients older than 60 only.

Surgery post COVID-19

Added: 11 Feb 2022
Updated: 4 Nov 2022

What is the evidence for timing of surgery, and outcomes following surgery, for people who have COVID-19?
  • Elective surgical procedures for individuals who test positive for COVID-19 should be delayed until the person recovers from the COVID-19 infection, and ideally, until seven weeks after the infection unless delaying the surgery increases risks of postoperative complications and mortality.
  • Elective surgery performed among fully vaccinated patients within four weeks of breakthrough COVID-19 infection is associated with a lower risk of complication compared to unvaccinated or partially vaccinated patients.
  • The Royal College of Surgeons of England emphasises that in the absence of Omicron-specific surgical recommendations, the recommendation of avoiding planned surgery within seven weeks after testing positive for COVID-19 should be maintained.


Added: 26 Sep 2022

What is the evidence for Paxlovid for treatment of COVID-19?
  • Paxlovid (PF-07321332/ritonavir) is an oral antiviral medicine that contains nirmatrelvir tablets co-packaged with ritonavir tablets.
  • In clinical trials, Paxlovid treatment was effective and beneficial in non-hospitalised and unvaccinated patients with COVID-19, who are at a high risk of disease progression and infected during the pre-Omicron period of the COVID-19 pandemic. However, it did not have a significant clinical benefit in people with a standard risk.
  • Two real-world studies from the Omicron-predominant period reported that Paxlovid treatment reduced the risk of disease progression (death or hospitalisation) in patients aged 65 or older. Both the studies found no clinical benefit of treatment in patients aged under 65. One study found no clinical benefit of Paxlovid treatment among fully vaccinated patients with regards to progression to severe disease, while the other found evidence of benefits regardless of vaccination or prior infection history in older adults.

Eating disorders and COVID-19

Added: 23 Aug 2022

What is the impact of the COVID-19 pandemic on the prevalence of eating disorders?
What are the trends in the presentation with eating disorders, especially among children and adolescents?
What are the innovative or new management strategies or pathways to care for patients with eating disorders?
What are the workforce implications and changes in workforce supports required?
  • Increase in the prevalence of eating disorders during the pandemic is attributed both to the worsening symptoms among patients with a prior history, and new onset symptoms and diagnosis in the community.1-5
  • The prevalence of recurring or exacerbated symptoms among patients with pre-existing eating disorders is 57% (meta-analysis of studies with patients with diagnosed eating disorders and who had their mental health disturbances evaluated) during the pandemic.

Archive COVID-19 transmission - retired living table

Added: 12 Aug 2022

What evidence is available about COVID-19 transmission?
  • This evidence table includes information on COVID-19 transmission concepts and current knowledge
  • It focuses on mode of transmission, setting-specific transmission, dose response, viral load, viral shedding and other relevant concepts.


Added: 6 Dec 2021
Updated: 4 Aug 2022

What is the evidence on the prevalence, presentation and management of long-COVID?
  • Recent prevalence estimates suggest that between 3.7% and 20.0% of individuals who experience COVID-19 infection develop long COVID.
  • In a clinical setting, there is no definitive test for long COVID, and diagnosis is based on ruling out other similar conditions.
  • Risk factors for long COVID may include: number of initial COVID-19 symptoms, certain co-morbidities such as hypertension, diabetes, obesity and asthma, and certain demographic factors such as being older, and living in more deprived areas.

Daily Evidence Digest

Rapid evidence checks are based on a simplified review method and may not be entirely exhaustive, but aim to provide a balanced assessment of what is already known about a specific problem or issue. This brief has not been peer-reviewed and should not be a substitute for individual clinical judgement, nor is it an endorsed position of NSW Health. Evidence checks are archived a year after the date of publication.

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